LTC3780 for MPPT solar charger poblems

[noob64]

Hi there,
I have some problems using LTC3780 for charging an lead-acid battery. I did manage to make a working buck-boost power supply with LTC3780 using the schematic form datasheet(for tests I managed to get 12,7V at 48W from 7-18V supply), but having it charging a battery from PV(power supply simulated) module failed.
The symptoms are:
1) Vin = 18V 1A, Vbat = 11.7V, Vout(set) = 13.8V I connect the LTC and Vin drops at 4-5V 1A, output diode get hot.
2) Vin = 18V 1A Vbat = 11.7V, Vout(set) = 12V I connect the LTC and Vin drops at 11.7V but charge, if load gets above 14-15W the LTC gets again in protection or something( Vin = 4-5V, max amps)
3) any combination where the output power(+ loses ) needed > input power bring the LTC bad working.
I see that the LTC3780 dose not want to drop his output voltage in any case, only about 0.4V max, and if the supply power cannot handle output power needed the LTC gets is some stupid mode.
I want to make the LTC3780 work with any input voltage/current and be able to charge whatever voltage battery have.
Here is my schematic(non populated current control):
https://i41.tinypic.com/2usyfjo.png

Sorry for my bad english.

 

[tgootee]

Need photo of your hardware layout.

 

[noob64]

Here my work in Eagle 6.4